GreehouseTruth Blog :: Messy Models, Climate's Conundrum
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The Mess with Models, Climate's Conundrum
A look at recent events that defy climate model projections of a warming world
Posted August 29, 2006 by Nathan Cool
If I were to ask you to name five things that global warming will do to our planet, I'd be willing to bet that "thickening of glaciers" was not among your list of projections. But, according to one recent study, that's exactly what's happening in some locations right now. Although at first glance this may seem counterintuitive--rising temperatures melt things, right?--it actually aligns well with clues of climate change that models and experts have predicted for quite some time. A well-known fact accepted by skeptics and believers alike is that as the world warms, more water evaporates from seas, rivers and lakes. This moisture has to eventually come down somewhere, and somewhere could be any place cold enough to snow; thus, it stands to reason that high altitude mountain peaks sporting white, frozen, glacial facades could gather some of the flakey white manna from the skies. In the majority of models, this though is expected to occur over Antarctica, but another recent report shows that the southernmost continent is not yet reaping these rewards. So, what's really going on here? Models say one thing yet reality seems to oppose these number-crunching leviathans.
In chapter 6 of my latest book, Is it Hot in Here?--The simple truth about global warming, I talk in depth about the world's hydrological cycle and the effects that a warming world has on precipitation rates. Myriad uncertainties abound when factoring in increased evaporation from our oceans: What about increased cloud cover that could dim the Sun's rays? What about added rainfall? And, in regards to recent reports, what about supplementary snowfall? As I point out quite often in Is it Hot in Here?, global warming is indeed a complex issue. In a world where we search for yes-or-no answers, science does not always lend itself well to reason, especially when it comes to a science that is very much still being understood.
Models have predicted for years that as Earth heats up, more and more water will fill the skies and eventually fall down to terra firma, primarily over Antarctica in the form of snow due to the greater moisture-holding capacity of warmer air in a warmer world. Bear in mind that although the Earth may be warming, it won't--at least any time soon--become so warm as to bring places like Antarctica above freezing. This land of ice, snow, penguins and leopard seals dips commonly to a brisk -55°F, or in other words, this great expanse of white is frequently frozen at temperatures hovering around 87 degrees below freezing. So as the world warms by a few degrees, sea ice and glaciers can easily melt during the warm seasons, yet winters would stay cold enough for snow to fall in acutely frigid places like Antarctica. And with an excessively moisture-laden atmosphere in a warmer world, increased snowfall would occur at the frostiest places on our planet. At least that's the theory anyways, and the vast majority of models agree on this point. When you think about it, it does seem logical, and researchers from Newcastle University in the U.K. think so as well.
An article published by the BBC titled "Global warming boost to glaciers" written just this past week, reports that researchers from Newcastle University have found increasing glacier thicknesses not in Antarctica, but in someplace no one (or no model) expected: the western Himalaya. Over the past century, this mountainous region near Pakistan has seen a thickening of its glaciers--something that seems quite uncanny when conjuring up images of global warming.
Yet while some areas of the world now seem to be getting a glacial growth spurt, other areas are not. In a recently published paper in the journal Science titled "Insignificant Change in Antarctic Snowfall Since the International Geophysical Year", researchers have found that over the past 50 years, as Earth has warmed, there has been no apparent increase in snowfall over Antarctica--something completely different from the Himalayan study, and something that challenges the predictions made by myriad models.
The combination of these seemingly conflicting studies provides not only added uncertainty into the picture of a heating planet; it also says something disheartening about the state of our climate right now. We know that many glaciers and ice sheets around the globe are melting, including great portions of Greenland, the Andes, Glacier National Park, Oregon's Mount Hood, and Kilimanjaro to name a few. This, as explained in Is it Hot in Here?, is one of the factors responsible for rises in sea level. This though, according to climate models, should be offset somewhat by added snowfall over Antarctica, which would take some of the water out of rising seas, deposited as snow on the South Pole. If though Antarctica is not getting additional snowfall as models originally predicted, then the offset is negligible, and the potential for additional rises in sea level become ever more worrisome.
If though some glaciers are getting additional snowfall, then the offset could be greater than expected, and sea level increases may be somewhat subdued. But who knows? The only crystal ball at the disposal of science at the moment are the climate models that take known knowledge, principles and data, and do their best to form a conclusion. But are they accurate? According to the recent studies on the growing Himalayan glaciers and the seemingly stagnant snowfall over Antarctica, the outcome of models becomes questionable. Observation though becomes all that more important.
It is important to note that even though these two recent studies dispute the findings of many climate models, numerous model projections have been exceptionally accurate. In a complex world where Mother Nature's intricacies have eluded science since science began, the field of climate change research, and the models used therein, are merely a part of a new, burgeoning field of understanding--something that is still being learned, and is based very heavily on theories, perfected over time from monitoring and measurements that calibrate future findings. Continuing to understand out planet's climate and its effects in a warming world will take many more years to fully understand. Not that this is an excuse to discount the theory of global warming; instead, as new discoveries unfold, it becomes all that more important to be watchful of the harbingers of a warming world that forewarn of things that will, or will not come to pass.
More information on the specific harbingers and bellwethers of global warming, the effects of melting ice, the hydrological cycle, snowfall, sea levels and other topics discussed in this blog can be found in my new book, Is it Hot in Here?--The simple truth about global warming. Click here to get your copy today.
